Formation of mature spores by B. anthracis ��Sterne and its lysogens under varying temperature and aeration conditions.

Cultures of B. anthracis ��Sterne (+ lysogenizing phage) and phage-cured derivatives were incubated in LD sporulation medium either 1 day at 37��C with aeration at 150 rpm or 5 days at 24��C with aeration at 75 rpm. The number of mature, heat-resistant spores per ml of culture was determined and is shown. Values are mean averages (�� standard deviation) from three to five experiments. ��*�� denotes the fact that experiments were performed at 30��C (rather than 37��C) to maintain the self-replicating form of pASD2.